1. Field of the Invention
The present invention relates to a radiofrequency contactor which electrically connects a radiofrequency semiconductor device and a testing circuit board when electrical characteristics of the radiofrequency semiconductor device are inspected and, more particularly, to a radiofrequency contactor capable of preventing a deterioration of a radiofrequency signal.
2. Background Art
When electrical characteristics of the radiofrequency semiconductor device are inspected, sending/receiving of radiofrequency signals is performed between a testing apparatus and the radiofrequency semiconductor device through wiring on a testing circuit board. Doing so requires electrical conduction between electrodes of the radiofrequency semiconductor device and the wiring on the testing circuit board. A contactor has been used for conduction between electrodes of a radiofrequency semiconductor device and wiring on a testing circuit board (see, e.g., Patent Document 1).    [Patent Document 1] Japanese Utility Model Laid-Open No. Hei 03-125503
The above-described contactor includes a testing circuit board, a pin contactor and a ground conductor opposed to the pin contactor. The testing circuit board is constituted of a wiring conductor and a lower surface ground conductor provided on a lower surface so as to face the wiring conductor. The characteristic impedance of the wiring conductor of the testing circuit board is adjusted to a certain value. The pin contactor and the ground conductor opposed to the pin contactor are respectively connected to the wiring conductor and the lower surface ground conductor of the testing circuit board.
When electrical characteristics of a radiofrequency semiconductor device are inspected by using the contactor, sending/receiving of a radiofrequency signal between the wiring conductor of the testing circuit board and the electrode of the radiofrequency semiconductor device is performed through the pin contactor. The sizes, shapes and placed positions of the pin contactor and the ground conductor opposed to the pin contactor are determined under constraints according to the size, structure, etc., of the radiofrequency semiconductor device. There is, therefore, a possibility of failure to match the characteristic impedance of the pin contactor to the characteristic impedance of the wiring conductor of the testing circuit board. In such a case, there is a problem that the radiofrequency signal deteriorates when passing through the pin contactor.